Leaking problem, can't find the culprit source

stuart45

There could be a slight crack where the render meets the black. It does look a bit damp in that area. You don't know what's behind the render, so there could be some gaps where the water can track in. It surprising how heavy wind driven rain can find it's way in to gaps. You could try some silicone where the black meets the render, up the sides as well.

warwick2001

stuart45 said:

There could be a slight crack where the render meets the black. It does look a bit damp in that area. You don't know what's behind the render, so there could be some gaps where the water can track in. It surprising how heavy wind driven rain can find it's way in to gaps. You could try some silicone where the black meets the render, up the sides as well.

Thanks for this, I'll get out there tomorrow, hopefully it'll have stopped raining by then.

Is there specialist silicone for render/brickwork, or will just a standard outdoor type one do?

stuart45

Any external one you have lying around. I'm only guessing where the water could be coming from, but it's worth a try. 
I have noticed in the past that window cills that don't have a drip groove often track water back into the inside.

warwick2001

Can you get/retrofit longer cills? I suspect having the dripping over the edge of the black reveal would be beneficial in this case

stuart45

You can, but you would have to ask Greenface about fitting them, not really my trade.

plumb1_2

It’s looks like the flashing is just fixed toi the brickwork under the rendering and sealed badly.
Rain will run down the wall hitting the bead stop, and then get sucked/blown in.
Imo chop off the render about 200mm high and fit a lead flashing on the wall so it covers the flashing what’s there now by 100mm. Then fit a new render stop bead and re render
And make sure the flashing goes 100 mm min passed the end of con

warwick2001

plumb1_2 said:

It’s looks like the flashing is just fixed toi the brickwork under the rendering and sealed badly.
Rain will run down the wall hitting the bead stop, and then get sucked/blown in.
Imo chop off the render about 200mm high and fit a lead flashing on the wall so it covers the flashing what’s there now by 100mm. Then fit a new render stop bead and re render
And make sure the flashing goes 100 mm min passed the end of con

Thanks for this @plumb1_2

Just checking, where you say "Then fit a new render stop bead and re-render" would this be directly above the new flashing, or would it sit slightly over the flashing? So, my terrible drawings show the options of either the stop bead just above the new flashing, or covering the new flashing slightly. Is this the kinda thing you mean? And would option A or B be the best?

Also, I'm assuming it would be wise to fit cavity trays (again!). I'm guessing these would go above the flashing, with the weep holes sitting a short distance above the stop bead? 

stuart45

The flashing should be in the same joint as the tray. This is the NHBC detail.
Some people put the stop bead just above the flashing, saying it's easier to replace the flashing like that.
Others put the stop bead just over the lead so it hold the lead in place better. Myself I put the bead over the lead to hold it place better, as the flashing should last at least as long as the render.

plumb1_2

Option B would be  best